1. Field of the Invention
This invention relates to a lead propelling mechanism for a mechanical pencil. More particularly, it relates to a lead propelling mechanism including a lead chuck having means for engaging an elastic member for tightening the chuck, and which is, therefore, easy to assemble.
2. Description of the Prior Art
A known mechanical pencil is shown by way of example in FIG. 1. It includes a lead holding tube 1 and a lead propelling mechanism 7 attached to the front end of the tube 1. The mechanism 7 comprises a lead chuck 2, a ring 3 for tightening the chuck 2, a sleeve 4, a spring 5 for absorbing any excessive writing pressure, and a spring 6 for tightening the chuck 2. When the lead propelling mechanism 7 is joined to the lead holding tube 1, the ring 3, the sleeve 4 and the spring 6 are first inserted over the chuck 2 past its rear end and the chuck 2 is, then, fitted into the front end of the tube 1. It is, however, often difficult to fit the chuck 2 in the tube 1 quickly, since the spring 6 abuts on the front end of the tube 1 and urges it back. It is necessary to hold the spring 6 by a finger or some mechanical device so that it may not push the tube 1 back. Thus, the assembly of the lead propelling mechanism with the lead holding tube has hitherto been a considerably inefficient job.